Current update on molecular cytogenetics, diagnosis and management of gastrointestinal stromal tumors

Nomogram for predicting cardiovascular mortality in patients with gastrointestinal stromal tumor: A population-based study

This research aimed to develop and validate a clinical nomogram for predicting the probability of cardiovascular death (CVD) in patients with gastrointestinal stromal tumors (GIST). Information regarding patients diagnosed with GIST was extracted from the surveillance, epidemiology, and end results database. The multivariable competing risk model and multivariable Cox regression model were utilized to determine the independent predictive factors. A comparison was made between the results obtained from the 2 models. A nomogram was built to visualize the competing risk model. The nomogram's performance was assessed utilizing concordance index, calibrate curve, decision curve analysis, and risk stratification. A total of 9028 cases were enrolled for final analysis, with CVD accounting for 12.8% of all deaths since GIST diagnosis. The multivariate analysis of competing risks revealed that age, chemotherapy and marital status were identified as independent risk factors for CVD in GIST individuals. The nomogram model exhibited good calibration and strong discriminative ability, indicating its effectiveness in predicting outcomes, with a concordance index of 0.788 (95% confidence interval: 0.753-0.823) in the training set, and 0.744 (95% confidence interval: 0.673-0.815) in the validation set. Decision curve analysis indicated that the prediction model had good clinical practicability. Additionally, risk stratification analysis efficiently divided GIST individuals into high- and low-risk populations for CVD. This was the first research to construct and validate a predictive nomogram using a competing risk model to estimate the individual probabilities of CVD in GIST patients. The nomogram can assist clinicians in making personalized treatment and monitoring plans.

Pilot Study by Liquid Biopsy in Gastrointestinal Stromal Tumors: Analysis of PDGFRA D842V Mutation and Hypermethylation of SEPT9 Presence by Digital Droplet PCR

Tissue biopsy remains the standard for diagnosing gastrointestinal stromal tumors (GISTs), although liquid biopsy is emerging as a promising alternative in oncology. In this pilot study, we advocate for droplet digital PCR (ddPCR) to diagnose GIST in tissue samples and explore its potential for early diagnosis via liquid biopsy, focusing on the PDGFRA D842V mutation and SEPT9 hypermethylated gene. We utilized ddPCR to analyze the predominant PDGFRA mutation (D842V) in surgical tissue samples from 15 GIST patients, correlating with pathologists' diagnoses. We expanded our analysis to plasma samples to compare DNA alterations between tumor tissue and plasma, also investigating SEPT9 gene hypermethylation. We successfully detected the PDGFRA D842V mutation in GIST tissues by ddPCR. Despite various protocols to enhance mutation detection in early-stage disease, it remained challenging, likely due to the low concentration of DNA in plasma samples. Additionally, the results of Area Under the Curve (AUC) for the hypermethylated SEPT9 gene, analyzing concentration, ratio, and abundance were 0.74 (95% Confidence Interval (CI): 0.52 to 0.97), 0.77 (95% CI: 0.56 to 0.98), and 0.79 (95% CI: 0.59 to 0.99), respectively. As a rare disease, the early detection of GIST through such biomarkers is particularly crucial, offering significant potential to improve patient outcomes.

Duodenal gastrointestinal stromal tumor presenting with life-threatening upper GI bleeding in a young patient: A case report and literature review

Key Clinical Message

Duodenal GISTs are rare and challenging tumors. Acute life-threatening upper GI bleeding is a possible presentation of duodenal GISTs. Surgery is the standard treatment for localized duodenal GISTs. Imatinib is an effective adjuvant therapy for duodenal GISTs.

Abstract

GIST is the most common mesenchymal neoplasm of the gastrointestinal tract, accounting for 1%-2% of gastrointestinal tumors. They originate from the interstitial cells of Cajal and are rare in patients younger than 30 years. The stomach is the most common site, followed by the small intestine and colon. GISTs are caused by a gain-of-function mutation in the proto-oncogene receptor tyrosine kinase, with activating mutations in KIT being the most common. Most GISTs are asymptomatic. Even if gastrointestinal bleeding is the most common complication life-threatening hemorrhage is extremely uncommon. We present a case of a 31-year-old male patient presented with massive active hematemesis and melena with hemorrhagic shock. The patient presented with massive hematemesis and melena of 1 h duration. Endoscopy showed pulsating active bleeding from the third part of the duodenum which was difficult to manage via endoscopy. Histopathologic evaluation showed spindle cell type GIST. Intraoperatively, there was a nodular mass with active bleeding on the third part of the duodenum. Duodenectomy with end-to-end anastomosis was done. Discharged with no postoperative complication and was put on imatinib. There are considerable challenges that arise in the diagnosis and treatment of duodenal gastrointestinal stromal tumors (GISTs) when they present with life-threatening upper gastrointestinal hemorrhage. In order to achieve the best possible outcomes for patients, it is crucial to have a comprehensive understanding of the clinical presentation, diagnostic methods, and treatment approaches.

Advanced gastrointestinal stromal tumor: reliable classification of imatinib plasma trough concentration via machine learning

AIM

Patients with advanced gastrointestinal stromal tumors (GISTs) exhibiting an imatinib plasma trough concentration (IM Cmin) under 1100 ng/ml may show a reduced drug response rate, leading to the suggestion of monitoring for IM Cmin. Consequently, the objective of this research was to create a customized IM Cmin classification model for patients with advanced GISTs from China.

METHODS

Initial data and laboratory indicators from patients with advanced GISTs were gathered, and the above information was segmented into a training set, validation set, and testing set in a 6:2:2 ratio. Key variables associated with IM Cmin were identified to construct the classification model using the least absolute shrinkage and selection operator (LASSO) regression and forward stepwise binary logistic regression. Within the training and validation sets, nine ML classification models were constructed via the resampling method and underwent comparison through the Brier scores, the areas under the receiver-operating characteristic curve (AUROC), the decision curve, and the precision-recall (AUPR) curve to determine the most suitable model for this dataset. Two methods of internal validation were used to assess the most suitable model's classification performance: tenfold cross-validation and random split-sample validation (test set), and the value of the test set AUROC was used to evaluate the model's classification performance.

RESULTS

Six key variables (gender, daily IM dose, metastatic site, red blood cell count, platelet count, and percentage of neutrophils) were ultimately selected to construct the classification model. In the validation set, it is found by comparison that the Extreme Gradient Boosting (XGBoost) model has the largest AUROC, the lowest Brier score, the largest area under the decision curve, and the largest AUPR value. Furthermore, as evaluated via internal verification, it also performed well in the test set (AUROC = 0.725).

CONCLUSION

For patients with advanced GISTs who receive IM, initial data and laboratory indicators could be used to accurately estimate whether the IM Cmin is below 1100 ng/ml. The XGBoost model may stand a chance to assist clinicians in directing the administration of IM.

Efficacy analysis of endoscopic treatment of giant gastric gastrointestinal stromal tumors (≥5 cm)

OBJECTIVE

To investigate the safety, feasibility and prognosis of endoscopic treatment of giant (≥5 cm) gastric gastrointestinal stromal tumors (gastric GISTs).

METHODS

Data from patients who underwent surgical resection of nonmetastatic gastric GISTs in our hospital from January 2016 to February 2022 were collected. The patients were divided into an endoscopic group and a laparoscopic group according to the surgical method. The clinical data and tumor recurrence information were compared between the two groups.

RESULTS

Eighteen cases were collected in the endoscopic group and sixty-three cases in the laparoscopic group. There were no significant differences in age, gender, tumor diameter, tumor growth site, tumor growth mode, clinical manifestations, risk classification or complication rate between the two groups (P > 0.05). The hospitalization cost, length of postoperative hospital stay and postoperative fasting time of the endoscopic group were less than those of the laparoscopic group, while the operation time was greater than that of the laparoscopic group (P < 0.05). In the endoscopic group, the follow-up was 33.50 ± 19.410 months, and no patients were lost to follow-up. The laparoscopic group was followed up for 59.07 ± 12.964 months, and eleven patients were lost to follow-up. There was no recurrence or metastasis in the two groups during the follow-up.

CONCLUSION

Endoscopic resection of gastric GIST with a diameter ≥5 cm is technically feasible. And it not only achieves a short-term prognosis similar to laparoscopic resection but also has the advantages of rapid postoperative recovery and low cost.

Efficacy of post-first-line agents for advanced gastrointestinal stromal tumors following imatinib failure: A network meta-analysis

BACKGROUND

Imatinib is the standard first-line treatment for advanced gastrointestinal stromal tumors (GISTs); however, most patients eventually develop imatinib resistance, leading to considerable clinical challenges. Few direct comparisons have been made between different post-first-line therapies on clinical efficacy in advanced GIST following imatinib failure.

METHODS

Databases including PubMed, Embase, Scopus, Google Scholars, and Cochrane Library from inception to February 2023 were retrieved for randomized controlled trials evaluating the clinical efficacy of different post-first-line agents for advanced GIST following imatinib failure. Network and conventional meta-analysis were carried out using Stata/MP 16.0.

RESULTS

Ripretinib showed significant improvement in progression-free survival (PFS) rates from the 2nd to the 12th month compared to placebo, while there was virtually no evidence that the rest active agents had a significant benefit at the 12th month. Masitinib, ripretinib, sunitinib, regorafenib, and pimitespib exhibited significantly longer median PFS than placebo, and pairwise comparisons indicated there were no significant differences among masitinib, ripretinib, and sunitinib. These post-first-line agents decreased the risk of disease progression or death by 65% (HR = 0.35, 95% CI: 0.26-0.47) compared to placebo. Ripretinib and sunitinib came into effect earlier and exhibited more consistent overall survival (OS) rate improvements than masitinib and pimitespib, while pairwise comparisons revealed no significant differences in these four active agents concerning the improvement in OS rate. These post-first-line agents decreased the risk of death by 39% (HR = 0.61, 95% CI: 0.44-0.83) over placebo for advanced GIST following imatinib failure.

CONCLUSION

The active agents in our analysis as post-first-line therapies are able to provide superior clinical efficacy, with improved PFS rate and OS rate at certain time points, as well as absolute values of PFS and OS for advanced GIST. Ripretinib might be the optimal recommendation as a post-first-line treatment for advanced GIST following imatinib failure.

Multi-slice spiral computed tomography in differential diagnosis of gastric stromal tumors and benign gastric polyps, and gastric stromal tumor risk stratification assessment

BACKGROUND

The biological characteristics of gastric stromal tumors are complex, and their incidence has increased in recent years. Gastric stromal tumors (GST) have potential malignant tendencies, and the probability of transformation into malignant tumors is as high as 20%-30%.

AIM

To investigate the value of multi-slice spiral computed tomography (MSCT) in the differential diagnosis of GST and benign gastric polyps, and GST risk stratification assessment.

METHODS

We included 64 patients with GST (GST group) and 60 with benign gastric polyps (control group), confirmed by pathological examination after surgery in PLA General Hospital, from January 2016 to June 2021. The differences in the MSCT imaging characteristic parameters and enhanced CT values between the two groups before surgery were compared. According to the National Institutes of Health’s standard, GST is divided into low- and high-risk groups for MSCT imaging characteristic parameters and enhanced CT values.

RESULTS

The incidences of extraluminal growth, blurred boundaries, and ulceration in the GST group were significantly higher than those in the control group (P < 0.05). The CT values and enhanced peak CT values in the arterial phase in the CST group were higher than those in the control group (P < 0.05). The MSCT differential diagnosis of GST and gastric polyp sensitivity, specificity, misdiagnosis rate, missed diagnosis rate, and areas under the curve (AUCs) were 73.44 %, 83.33%, 26.56%, 16.67%, 0.784, respectively. The receiver operating characteristic curves were plotted with the arterial CT value and enhanced peak CT value, with a statistical difference. The results showed that the sensitivity, specificity, misdiagnosis rate, missed diagnosis rate, and AUC value of arterial CT in the differential diagnosis of GST and gastric polyps were 80.18%, 62.20%, 19.82%, 37.80%, and 0.710, respectively. The sensitivity, specificity, misdiagnosis rate, missed diagnosis rate, and AUC value of the enhanced peak CT value in the differential diagnosis of GST and gastric polyps were 67.63%, 60.40%, 32.37%, 39.60%, and 0.710, respectively. The incidence of blurred lesion boundaries and ulceration in the high-risk group was significantly higher than that in the low-risk group (P < 0.05). The arterial phase and enhanced peak CT values in the high-risk group were significantly higher than those in the low-risk group (P < 0.05).

CONCLUSION

Presurgical MSCT examination has important value in the differential diagnosis of GST and gastric benign polyps and can effectively evaluate the risk grade of GST patients.

Rectal gastrointestinal stromal tumor with metachronous liver metastasis demonstrated no relapse after multidisciplinary team discussion and comprehensive treatment: a case report

Background

This study sought to explore the role and significance of multidisciplinary team (MDT) discussion and comprehensive treatment in the diagnosis and treatment of a gastrointestinal stromal tumor (GIST) with liver metastasis. For GIST patients with liver metastasis, MDT can evaluate whether the liver metastasis is resectable, so as to formulate accurate treatment goals and the best diagnosis and treatment plan.

Case Description

A 53-year-old male patient with localized rectal GIST with metachronous liver metastasis (MLM) was admitted to Yunnan Cancer Hospital in October 2014. At the 1st visit, he was diagnosed with locally advanced rectal GIST, and a MDT discussion was held by departments of colorectal surgery, imaging, pathology and oncology. The tumor shrank after neoadjuvant targeted treatment with imatinib. A local resection of the rectal GIST was successfully performed via the anal approach. R0 resection was achieved and the function of the anal sphincter was preserved. Following the operation, oral imatinib treatment was discontinued after 2 years. The patient developed isolated liver metastasis 6 months later. After the MDT discussion by departments of colorectal surgery, hepatobiliary surgery, imaging, pathology, and oncology, R0 resection of the liver metastasis was achieved. After the operation, sunitinib was administered for 4.5 years. The patient's overall survival (OS) has reached 7.5 years. No tumor recurrence or metastasis was found in the re-examinations. The follow-up is ongoing.

Conclusions

Targeted therapy combined with surgery is the most suitable way to cure GIST patients with liver metastasis. More importantly, the multi-disciplinary management and the standardized diagnosis and treatment of GIST patients with liver metastasis through MDT discussion can improve the quality of life and prolong the survival of patients.

Development of an innovative nomogram of risk factors to predict postoperative recurrence of gastrointestinal stromal tumors

BACKGROUND

There are many staging systems for gastrointestinal stromal tumors (GISTs), and the risk indicators selected are also different; thus, it is not possible to quantify the risk of recurrence among individual patients.

AIM

To develop and internally validate a model to identify the risk factors for GIST recurrence after surgery.

METHODS

The least absolute shrinkage and selection operator (LASSO) regression model was performed to identify the optimum clinical features for the GIST recurrence risk model. Multivariable logistic regression analysis was used to develop a prediction model that incorporated the possible factors selected by the LASSO regression model. The index of concordance (C-index), calibration curve, receiver operating characteristic curve (ROC), and decision curve analysis were used to assess the discrimination, calibration, and clinical usefulness of the predictive model. Internal validation of the clinical predictive capability was also evaluated by bootstrapping validation.

RESULTS

The nomogram included tumor site, lesion size, mitotic rate/50 high power fields, Ki-67 index, intracranial necrosis, and age as predictors. The model presented perfect discrimination with a reliable C-index of 0.836 (95%CI: 0.712-0.960), and a high C-index value of 0.714 was also confirmed by interval validation. The area under the curve value of this prediction nomogram was 0.704, and the ROC result indicated good predictive value. Decision curve analysis showed that the predicting recurrence nomogram was clinically feasible when the recurrence rate exceeded 5% after surgery.

CONCLUSION

This recurrence nomogram combines tumor site, lesion size, mitotic rate, Ki-67 index, intracranial necrosis, and age and can easily predict patient prognosis.

Laparoscopic retroperitoneal resection of the duodenal gastrointestinal stromal tumors in neurofibromatosis type 1; Case Report and literature review

Background

Neurofibromatosis type 1, also known as NF1, is a disorder that is passed down in an autosomal dominant manner. It manifests in a wide variety of tumors and affects several organ systems. It is expected that those carrying the NF1 gene will develop a rare mesenchymal tumor known as a gastrointestinal stromal tumor (GIST) more than general population.

Case report

This research discusses a 42-year-old female patient with NF1 who was identified with a duodenal GIST but clinically and radiographically misinterpreted as having a retroperitoneal neurofibroma. She had minimally invasive retroperitoneal laparoscopic surgery to remove the tumor and primary anastomosis of the affected duodenal wall. A spindle cell GIST was entirely excised during surgery, as indicated by the pathologist. As a consequence of dialogue at a multidisciplinary team meeting, the patient was discharged from the hospital on the fourth postoperative day and is presently undergoing regular clinical follow-up.

Conclusion

Anatomically problematic sites, such as the duodenal GIST in NF1 patients, can be treated safely with the laparoscopic retroperitoneal approach even when retroperitoneal neoplasia arises from the intrabdominal structure and protrudes into the retroperitoneal region.

Clinicopathological features of Gastrointestinal Stromal Tumors and review of the literature

Objective: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasias of the gastrointestinal system (GIS). The malignancy potential of GISTs may vary ranging from indolent tumors to progressive malignant tumors. This study aims to define clinicopathological and immunohistochemical features of GISTs diagnosed in our institute with a review of the literature. Method: A total of 28 GIST cases were included in the study. The Hematoxylin&Eosin stained slides of surgical resection materials and cell blocks and immunohistochemistry performed slides were reviewed by a pathologist. The immunohistochemical expression with CD117, DOG-1, CD34, SMA, and S100 was scored between 0 and 3 points according to staining intensity. Descriptive statistics were used in the study. The demographic data, prognostic histopathological, and immunohistochemical findings are evaluated with the literature indications. Result: Eleven of the cases were male and seventeen were female. The age range was 18-88. The most common site of GISTs was the stomach, followed by the small intestine, colorectal region, and, esophagus. Twenty of the tumors were resected surgically, four were endoscopic biopsy material and four were fine-needle aspiration biopsies. The tumor size in measurable materials ranged from 0,2 to 22 cm. The mitotic count in 50 HPF ranges from 0 to 10. Seven of the GISTs were high grade and the remaining 21 were low grade. The majority of the cases were composed of spindle cells, 3 were epithelioid and 3 were the mixed type with spindle and epitheloid cells. Conclusion: A variety of criteria has been proposed to estimate the malignancy potential of GISTs and predict prognosis but definite prognostic criteria remain uncertain. Further studies with larger series of GISTs consisting of different types of biopsy materials may help define criteria to predict prognosis precisely.